Abstract
A 83-year-old man visited our hospital with a right breast tumor. The tumor of about 2cm in diameter was present in the right breast ACE area. Breast ultrasonography showed a high echoic and round tumor beneath the left nipple. The chest CT showed 23mm mass with a clear border in the right mammary gland. There were no invasions to the skin and muscle and no swallen lymph nodes. In addition to the breast cancer, a further examination revealed prostatic cancer with bone metastases. Modified radical mastectomy was performed. For prostate cancer, we decided to perform hormone therapy. The pathological diagnosis was mucinous carcinoma of the breast. Breast cancer and prostatic cancer are hormone-dependent cancer and breast cancer is different from prostatic cancer in reaction to hormone environment. So, it is difficult to choose post-operative adjuvant hormone therapy (endocrine therapy) in such individual. Therapeutic method is not established yet because there are few reports of cases in which two cancer coexist simultaneously.
